The present invention relates generally to heads for use in a magnetic storage drive. In particular, this invention relates to methods and structures for reader gaps.
A read/write head in a disc drive typically includes a magnetoresistive (MR) read sensor that is deposited between insulating layers and magnetic shield layers. The magnetoresistive read sensor typically includes a magnetoresistor stack, electrical contacts and one or more bias magnets that magnetically bias the magnetoresistor stack.
The magnetoresistor and electrical contacts carry an electrical bias current. As magnetically stored data on a disc flies by the magnetoresistor, the magnetoresistor generates readback pulses that have a readback amplitude that represents the data stored on the disc. The readback amplitude is generally proportional to the bias current. The bias current amplitude and read sensor dimensions are chosen in a way that considers the needs of the read channel electronics for a high amplitude readback pulse. The bias current amplitude and read sensor dimensions are also chosen in a way that considers the need to limit heating to prevent damage to the magnetoresistor. The need for a high amplitude readback pulse and the need to limit heating conflict with one another and limit the performance that can be achieved with conventional magnetoresistive read sensors.
As track density on the disc increases, the reader dimensions must be made correspondingly smaller and the conflict between thermal and electrical design requirements increases beyond the capabilities of current designs.
A magnetic read sensor and a method of making such a magnetic read sensor are needed that provide an improved combination of thermal and electrical characteristics in a read/write head usable with higher areal densities.
Disclosed is a read/write head that comprises a slider substrate and a read shield. The read shield includes a bottom magnetic shield layer on the slider substrate and a shared magnetic shield layer that is spaced apart from the bottom magnetic shield layer.
The read/write head comprises a write head disposed on the shared magnetic shield layer. The read/write head also comprises a read sensor disposed between the bottom magnetic shield layer and the shared magnetic shield layer. The read sensor is spaced apart from the read shield by reader magnetic gaps.
The read/write head also comprises electrically insulating layers on the read sensor. The electrically insulating layers form a thermal resistance between the read sensor and the read shield.
The read/write head also comprises a thermally conducting nonmagnetic layer deposited on the read shield in a first one of the reader magnetic gaps. The thermally conducting nonmagnetic layer reduces the thermal resistance without a corresponding reduction in the reader magnetic gaps.
These and various other features as well as advantages that characterize the present invention will be apparent upon reading of the following detailed description and review of the associated drawings.